We were heading west on I-8 & were approx 60 east of Yuma & south of the Yuma Proving Ground at apporx 1900 hrs. I looked out my window & saw a black object very high in the sky. The object did not reflect the sunlight as the planes flying near-by were, nor did it have any flashing lights as all aircraft should. It was so high I could not make out the shape. It appears to be suspended from something but is way too high to be hanging. It did not seem to move. Keep in mind we were travelling at 80 MPH & my 15 yr old son & I watched it for approx 45mins & it was still in full view. My husband was driving but saw it as well. I have a friend who is from that area & travels to Yuma once or twice or month, I asked her about the object & she says her family sees it all the time. My father works for the military & has a Top Secret security clearance but of course he couldn't (or wouldn't) tell me anything. I'm sure it has something to do with the military (I hope) but I grew up on military bases & have never noticed anything like that before.